This is a request for conference support for that portion of the upcoming 8th International Histocompatibility Workshop which will have to do with aging and the diseases of aging. The aging part will consist in HLA typing of about 100 persons over 90 years of age to estimate whether certain histocompatibility genes have survival value in humans. Diseases to be typed will include familial and nonfamilial Alzheimer's disease, Bloom's syndrome, Werner's syndrome, Fanconi's anemia, and xeroderma pigmentosum. Applicant's role in the Workshop will be to set up, guide, and handle the data generated internationally for these diseases plus the older individuals. The Conference will provide in effect a world-wide registry of collaborative units focusing upon these rare but gerontologically important entities. Further work can then be undertaken such as, for example, DNA-repair studies (as measured by unscheduled DNA synthesis) to unravel the genetics of the diseases by family analysis.